I purchased a Dell Studio 1737 Laptop from Best Buy with the 5 yr full waranty. My laptop quit charging and I had to go through Dell to get a service tech to replace parts on the computer. The Win7 upgrade is a security patch that will reconfigure your settings for Win& but your computer will have upgrade issues due to the fact it is recognized on a Windows 6 platform (Vista) rather than the new Win 7. I had to reinstall Vista to correct the issue.
I paid $65 dollars for a service call to be provided within 72 hrs. Over a week later the tech arrived and gave me the information needed to complain and get a refund, which never happened. I continue to have issues with the laptop. But rather than buy a full version of Win 7 and lose all my documents, pictures and music again, I purchased another HP Pavilion, my 5th. I did back up my computer on a Toshiba Terabyte external drive. It no longer recognized my Dell, so I access the files one at a time changing the security of the file prior to copying back onto computer.
When I hooked the external drive up to the Dell after the "upgrade" I could not restore the files using the Toshiba Software or Windows. I lost 6 years of research, school work, family photos, financial records and more. It was the most expensive lesson learned.